wrote:

Some people insist low octane fuel burns FASTER, which might put more
heat in the cyl - but I have seen info from fuel engineers
thatndisputes this theory.

Higher octane fuel is used to make the flame-front advance more slowly and
smoothly across the combustion chamber, thus eliminating "knock". The flame
starts at the spark plug and fans out from there. What you want is less of an
explosion, and more of a steady increase in pressure in the combustion chamber.
That's what higher octane does.

Disclaimer: not a professional in this field.